Theory of the quantum confinement effect on excitons in quantum dots of indirect-gap materials

Toshihide Takagahara, Kyozaburo Takeda

Research output: Contribution to journalArticle

854 Citations (Scopus)

Abstract

The quantum confinement effect on excitons in quantum dots of indirect-gap materials is investigated and a mechanism that induces an indirect-to-direct conversion of the character of the optical transition is clarified. The exciton transition energy and the exciton binding energy are calculated and found to be in good agreement with experimental results on Si and Ge nanostructures. The large exciton binding energy in Si and Ge quantum dots suggests that the photoluminescence from these nanostructures is of excitonic origin even at room temperature. The estimated radiative lifetime of excitons is strongly size dependent and varies from nanosecond to millisecond corresponding to the diameter from ∼10 to ∼30. These theoretical results suggest strongly the importance of the quantum confinement effect in the luminescence processes of porous Si.

Original languageEnglish
Pages (from-to)15578-15581
Number of pages4
JournalPhysical Review B
Volume46
Issue number23
DOIs
Publication statusPublished - 1992
Externally publishedYes

Fingerprint

Quantum confinement
Excitons
Semiconductor quantum dots
quantum dots
excitons
Binding energy
Nanostructures
binding energy
Optical transitions
radiative lifetime
Electron transitions
optical transition
Luminescence
Photoluminescence
LDS 751
luminescence
photoluminescence
room temperature
Temperature

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Theory of the quantum confinement effect on excitons in quantum dots of indirect-gap materials. / Takagahara, Toshihide; Takeda, Kyozaburo.

In: Physical Review B, Vol. 46, No. 23, 1992, p. 15578-15581.

Research output: Contribution to journalArticle

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